Fluid fuel burner assembly



April 20, 1965 Filed March '15, 1962 FIG. I

R. D. REED 3,179,151

FLUID FUEL BURNER ASSEMBLY 2 Sheets-$heet 1 INVENTOR ROBERT D. REED .L au

ATTORNEY R. D. REED FLUID FUEL BURNER ASSEMBLY Am-i120, 1965 2 Sheets-Sheet 2 Filed March 15, 1962 INVENTOR ROBERT D. RE E D ATTORNEY United States Patent 3,179,151 FLUID FUEL BURNER ASSEMBLY Robert D. Reed, Tulsa, Okla, assignor to John Zink Company, Tulsa, Okla, a corporation of Delaware Filed Mar. 15, 1962, Ser. No. 179,912 3 Claims. (Cl. 158-15) The present invention relates to a burner assembly for the combustion of gaseous fuel or liquid fuel and the invention more specifically pertains to a burner assembly provided with means for guiding controlled quantities of air in separate paths to the downstream portions of the burner head to relievelow pressure conditions that develop in operation of the burner and thereby avoid the heated gases and burning fuel from returning to the presence of the burner elements and to carry heat from components of the burner assembly.v

The prior art includes burners for the combustion of gaseous and liquid fuels and such prior devices provide for delivery of secondary air to the presence of the burner head. The discharge of the fuel develops low pres sure conditions as a result of the velocity of the discharge of the fuel so that there has been a tendency in the past ctor heat to return to the presence of the burner parts. The low pressure conditions have the further disadvantage of influencing the shape of the flame and of causing the partially burned liquid fuel to return to the presence of the burner to provide coke accumulations.

It is an object of the present invention to provide a burner assembly which includes means for guiding air for movement downstream of the burner and in several paths so as to relieve the low pressure conditions which develop downstream of the burner assembly and to avoid the burning fuel and hot products of combustion from being drawn into the presence of the burner elements and to supply cooling air over parts of the burner assembly.

Another object of the invention is to provide a burner assembly wherein the discharge ports are so spaced from each other and so oriented as to prevent the low pressure area developed adjacent the exit end of one discharge port from mingling with the low pressure area developed adjacent the exit end of another discharge port and thereby avoid the development of a low pressure area common to all of the discharge ports and to FIG. 1 is an axial sectional view of a burner assembly embodying the invention.

FIG. 2 is an enlarged end view of the burner head unit and taken approximately on the line 2-2 of FIG. 1.

FIG. 3 is a longitudinal sectional view of the burner head unit taken on the line 33 of FIG. 2. V FIG. 4 is a transverse sectional view on a smaller scale and taken on the line 4-4 of FIG. 3.

FIG. 5 is an'enlarged sectionalview of one of the burner bosses taken on the line 5-5 of FIG. 2.

FIG. 6 is an elevational view on a smaller scale of the upstream end of the burner assembly.

An embodiment of the burner assembly is shown in the drawings which is of a type that may be supported on a Wall or floor 11 encasing a fire box or furnace chamber. The burner assembly is so constructed and 3,179,151 Patented Apr. 20,1965

mounted on the wall 10 that the heat developed by the burning fuel is projected into the fire box through an opening 11. In the embodiment illustrated the burner assembly is supported on the wall 10 by means of a thimble 12 which may be secured to the wall by means of cap screws 14. A disc-shaped member 16 is supported in spaced relationship from the outer face of the wall 10 by means of circumferentially spaced elongated cap screws or bolts 15 equipped with spacer elements 17. Open areas are provided between the elements 17 for the entry of air which moves into the furnace and the manner of the paths in which air is guided to a portion of the burner assembly is more fully hereinafter described.

A cylindrical housing member 18 of relatively large diameter extends through a central opening in the discshape member 16 and is supported thereon. The housing member 18 is provided with circumferentially spaced openings 19 as shown in FIG. 1. The downstream end of the housing member 18 carries a frusto-conical shaped shield 21 which may be secured to the exterior of the housing member 18 in any suitable manner. portion of the shield extends outwardly beyond the perimeter of the housing member 18 as will be appreciated from a consideration of FIG. 3.

A tube 22 of smaller diameter than the housing member 18 is arranged concentrically therewithin to provide an annular space 23 between theinterior of the housing member 18 and the exterior of the tube 22. The upstream end of the housing member 18 beyond the discshaped member 16 is closed by means of a ring shape member 24 so that there is no possibility of air entering the upstream end of the housing member 18 and the ring shaped member 24 serves to maintain the upstream end of the tube 22 coaxially within the housing member 18.

A tubular member 26 of smaller diameter. than the tube 22 is arranged concentrically thercwithin as shown in FIG. 3. The upstream end of the tubular member 26 extends beyond the corresponding end of the tube 22 as shown in FIG. 1. A ring shaped member 27 closes the end of the tube 22 around the tubular member 26. An-

other annular passage 28 is provided between the inner surface of the tube .22 and the exterior of the tubular member 26. This annular space is provided for guiding gaseous fuel under pressure to the burner head. It is for this purpose that a conduit fitting 29 is provided on the tube 22 for supplying gaseous fuel under pressure into the annular space 28.

A burner head for the gaseous fuel includes a tubular element 32 which has substantially the same diameter as the tubular member 26 and is jointed to the downstream end thereof in any suitable manner such as by means of an annular weld indicated at 33 in FIG. 3. The burner head includes a spherical-shaped wall portion 34 and the perimeter of the wall 34 is substantially in alignment with the wall of the tube 22 to provide a hollow annular chamber 36 within the burner head.

The burnerhea d for the gaseous fuel includes a plurality of hollow bosses or arms 37 which extend radially from the perimeter of the wall 34. The hollow arms or bosses 37 are closed at their freeends by means of end walls 38. An annular wall 39 closes the perimeter of the chamber 36 between the bosses or arms 37 and the wall 39 has a diameter substantially like that of the tube 22. The wall 39 is jointed to the tube 22 in any suitable manner such as by means of an annular weld indicated at 41 in FIG. 3. The bosses or arms 37 are in open communication with the chamber 36 whereby the gaseous fuel supplied under pressure into the annular space 28 moves into the chamber 36 and into all of the bosses or hollow arms 37.

Each boss or arm 37 is provided with discharge ports The conical bosses.

42. In the embodiment illustrated "two discharge ports 42 are provided in each boss. The discharge ports 42 may be arranged as a row and in alignment radially of each boss 37. The axis of each discharge port 42 is arranged at an acute angle of about sixty degrees with respect to a plane 43 which is at right angles to the axis of the assembly and defines the center of the arms 37 and this relationship of the ports to an arm 37 is best shown in FIGS. 2 and 5.

The burner assembly may include a burner head for liquid fuel and which may take the form of a nozzle 4-6 carried by a pipe 47 which is arranged within the tubular member 26. Liquid fuel is supplied to the nozzle 46 through the pipe 47. The nozzle 46 is maintained coaxially of the burner head for gaseous fuel by means of lugs 45. Discharge orifices 48 are provided in the nozzle 46. The discharge orifices are desirably arranged in a circular outline as shown in FIG, 2 and the axes of the orifices 48 are such to discharge the liquid fuel in a flaring conical pattern proceeding downstream from the nozzle 46.

A disc-shaped baflie 51 is mounted for sliding movement on the housing member 18 for controlling the volume of air admitted for movement into the presence of the fuel through the annular area between the housing 13 and the opening 11. This air moves in the direction of the arrows 52 in FIG. 1. and in the annular space exteriorly of the housing 18 and engages the conical shield 21. The

perimeter of the shield 21 deflects this air outwardly and sures additional low pressure influences are developed which add to the low pressure condition represented in phantom lines. If this low pressure condition is not relieved by'an inflow of air from another location a number of disadvantageous conditions develop in operation of the burner unit or units. The burning gaseous fuel and the hot gases unless prevented are drawn back into the low pressure zone to overheat the burner parts promoting rapid deterioration of the structure of the burner. When liquid fuel is being burned a further disadvantage develops because the partially burned liquid is drawn into the low pressure zone to form coke which accumulates rapidly and to such an extent that operation of the burner is impaired.

A feature of the'present burner assembly pretains to the provision of means for relieving the low pressure condition zone and its attendant disadvantages. In a burner assembly embodying the invention structure is provided for the delivery of air into the annular space 23 which moves in the direction indicated by the arrows 53 in FIG. 3. The quantity of air entering the openings 19 is dependent upon the low pressure condition downstream of the burner assembly. This additionalenergy is substantially proportional to the quantity of fuel burned so that the beneficial effects of the flow of air in the annular space 23 is substantially proportional to the need of air at the downstream portion of the burner assembly. The air flowing in the annular space 23 passes over the arms or bosses 37 as indicated by the arrows in FIG. 5 to dissipate heat which tends to build up in the arms or Since the discharge ports 42 are arranged on one side of each boss or arm 37 there is no interference with this flow of the air so that there is a free sweep of air over the entire surface of each arm serving to cool the structure. The air passing between the arms 37 supplies air directly into the low pressure zone to relieve the low pressure condition downstream of the burner assembly. The relief of the low pressure is not complete but the low pressure is relieved to an extent that this zone no longer causes excessive return of the heated gases or the partially burned liquid fuel to the burner elements. Any heating of the burner parts that may occur is dissipated by the cooling action of the air moving downstream in the annular passage 23.

The fuel escaping through the discharge ports 42. at high velocity sets up a low pressure area around each fuel jet adjacent the exit end of the associated discharge port. The discharge ports 42 in one boss or arm 37 are spaced from the discharge ports 42 of an adjacent boss or arm 37. This displacement taken with the relief of the low prcssurebetween adjacent bosses resulting from the air flowing from the annular space 23 prevents an interexchange of the low pressure set up around each discharge fuel stream to prevent an interlock of the separated low pressure areas. The gaseous fuel escaping through the discharge ports 42 provides for whirling of the gaseous fuel discharged from all of the bosses or arms 37 to promote mixture or" the fuel with the air supplied through the annular space 23 to further prevent an interexchange of the low pressure areas developed around each high velocity fuel stream. The liquid fuel discharged through each orifice 48 tends to set up low pressure conditions therearound and these tend to interexchange to provide a low pressure area which is common to all of the fuel jets. Th' condition if not avoided would cause all of the fuel streams to turn arcuately in the direction of the axis of the burner assembly and alter the designed shape of the flame. The supply of air through the annular space 23 relieves the low pressure zone set up by the discharge of the liquid fuel and serves to. prevent the interexchange of the low pressure area developed about each fuel jet.

While the invention has been described with reference to specific structural features and with regard to one gen eral assembly of the components it will be appreciated that changes may be made in the elements as well as the overall combination. Such changes and others may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

What I claim and desire to secure by Letters Patent is:

1. In a fuel burner assembly a wall having an opening therethrough, a disc-shaped member supported in spaced ing, a tube positioned coaxially within said housing and of smaller diameter providing an annular space between the perimeter of said tube and the interior of said housing member, a tubular member coaxially within said tube and of smaller diameter providing an annular passage between the exterior of the tubular member and the interior of said tube, a burner head including means providing an annular chamber supported by a downstream end of said tube and by the downstr eam end of said tubular member, a plurality of hollow bosses extending radially from said means in communication with said chamber with free ends of said bosses terminating adjacent the interior of said housing member, said bosses having discharge ports, means for supplying gaseous fuel under pressure through said annular passage into said chamber and into said bosses for escape through said discharge ports, means upstream of said disc-shaped member extending between the exterior of said tube and the interior of said housing closing the upstream end of said annular space, said housing having circumferentially spaced openings therein located upstream of the outer face of said wall and downstream of said disc-shaped member for the entry of air into said annular space and for movement over said bosses, andbafiie means movable along said housing member for apportioning air between said annular area and said openings.

2. In a fuel burner assembly according to claim 1 in- 3,179,151 5 6 eluding a frusto-conical shield carried at the exterior of 1,643,788 9/27 Seaver 158-11 said housing member at the downstream end thereof. 1,678,086 7/28 Sehrader 158-409 XR 3. In a fuel burner assembly according to claim 1 2,344,936 3/44 Zink. wherein the interior of said tubular member is open and 2,964,121 12/60 Zink. serves as a guide tube for a burner nozzle and a supply 5 FOREIGN PATENTS P1P e therefor' 377 220 6/23 G References Cited by the Examiner ermany' UNITED STATES PATENTS IAMES W. WESTHAVER, Primary Examiner.

1,513,260 10/24 Mooring. 1O PERCY L. PATRICK, Examiner. 

1. IN A FUEL BURNER ASSEMBLY A WALL HAVING AN OPENING THERETHROUGH, A DISC-SHAPED MEMBER SUPPORTED IN SPACED RELATIONSHIP FROM AN OUTER FACE OF SAID WALL, A CYLINDRICAL HOUSING MEMBER OF SMALLER CROSS SECTION THAN SAID OPENING SUPPORTED BY SAID DISC-SHAPED MEMBER AND EXTENDING INTO SAID OPENING TO PROVIDE AN ANNULAR AREA BETWEEN THE PERIPHERY OF SAID HOUSING AND THE PERIMETER OF SAID OPENING, A TUBE POSITIONED COAXIALLY WITHIN SAID HOUSING AND OF SMALLER DIAMETER PROVIDING AN ANNULAR SPACE BETWEEN THE PERIMETER, OF SAID TUBE AND THE INTERIOR OF SAID HOUSING MEMBER, A TUBULAR MEMBER COAXIALLY WITHIN SAID TUBE AND OF SMALLER DIAMETER PROVIDING AN ANNULAR PASSAGE BETWEEN THE EXTERIOR OF THE TUBULAR MEMBER AND THE INTERIOR OF SAID TUBE, A BURNER HEAD INCLUDING MEANS PROVIDING AN ANNULAR CHAMBR SUPPORTED BY A DOWNSTREAM END OF SAID TUBE AND BY THE DOWNSTREAM END OF SAID TUBULAR MEMBER, A PLURALITY OF HOLLOW BOSSES EXTENDING RADIALLY FROM SAID MEANS IN COMMUNICATION WITH SAID CHAMBER WITH FREE ENDS OF SAID BOSSES TERMINATING ADJACENT THE INTERIOR OF SAID HOUSING MEMBER, SAID BOSSES HAVING DISCHARGE PORTS, MEANS FOR SUPPLYING GASEOUS FUEL UNDER PRESSURE THROUGH SAID ANNULAR PASSAGE INTO SAID CHAMBER AND INTO SAID 